Tool with articulation lock

ABSTRACT

The invention provides surgical or diagnostic tools and associated methods that offer user control for operating remotely within regions of the body. These tools include a proximally-located actuator for the operation of a distal end effector, as well as proximally-located actuators for articulational and rotational movements of the end effector. Control mechanisms and methods refine operator control of end effector actuation and of these articulational and rotational movements. An articulation lock allows the fixing and releasing of both neutral and articulated configurations of the tool and of consequent placement of the end effector. The tool may also include other features. A multi-state ratchet for end effector actuation provides enablement-disablement options with tactile feedback. A force limiter mechanism protects the end effector and manipulated objects from the harm of potentially excessive force applied by the operator. A rotation lock provides for enablement and disablement of rotatability of the end effector.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.11/787,543 (filed Apr. 16, 2007), which is a continuation in part ofU.S. patent application Ser. No. 11/181,445 (filed Jul. 13, 2005), nowU.S. Pat. No. 7,615,066 B2, which is a continuation of U.S. patentapplication Ser. No. 10/444,769 (filed May 23, 2003), now U.S. Pat. No.7,090,637 B2, the disclosures of which are incorporated herein byreference. This application is also a continuation in part of U.S.patent application Ser. No. 11/121,668 (filed May 3, 2005), which claimspriority to U.S. Patent Application No. 60/630,912 (filed Nov. 24,2004). U.S. patent application Ser. No. 11/787,543 is further related tothe following concurrently filed U.S. patent applications: U.S. patentapplication Ser. No. 11/787,607 (filed Apr. 16, 2007; “Tool withrotation lock” of Hinman and Danitz), U.S. patent application Ser. No.11/787,599 (filed Apr. 16, 2007, “Tool with end effector force limiter”of Hinman and Bertsch), U.S. patent application Ser. No. 11/787,605filed Apr. 16, 2007, “Tool with multi-state ratcheted end effector” ofHinman), and U.S. patent application Ser. No. 11/787,608 (filed Apr. 16,2007, “Articulating tool with improved tension member system” ofHegeman, Danitz, Bertsch, Alvord, and Hinman).

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

FIELD OF THE INVENTION

This invention relates to articulating mechanisms and applicationsthereof, including the remote guidance and manipulation of surgical ordiagnostic tools.

BACKGROUND OF THE INVENTION

Surgical procedures such as endoscopy and laparoscopy typically employinstruments that are steered within or towards a target organ or tissuefrom a position outside the body. Examples of endoscopic proceduresinclude sigmoidoscopy, colonoscopy, esophagogastro-duodenoscopy andbronchoscopy. Traditionally, the insertion tube of an endoscope isadvanced by pushing it forward, and retracted by pulling it back. Thetip of the tube may be directed by twisting and general up/down andleft/right movements. Oftentimes, this limited range of motion makes itdifficult to negotiate acute angles (e.g., in the rectosigmoid colon),creating patient discomfort and increasing the risk of trauma tosurrounding tissues.

Surgical procedures such as endoscopy and laparoscopy typically employinstruments that are steered within or towards a target organ or tissuefrom a position outside the body. Examples of endoscopic proceduresinclude sigmoidoscopy, colonoscopy, esophagogastroduo-denoscopy, andbronchoscopy, as well as newer procedures in natural orificetransluminal endoscopic surgery (“NOTES”). Traditionally, the insertiontube of an endoscope is advanced by pushing it forward, and retracted bypulling it back. The tip of the tube may be directed by twisting andgeneral up/down and left/right movements. Oftentimes, this limited rangeof motion makes it difficult to negotiate acute angles (e.g., in therectosigmoid colon), creating patient discomfort and increasing the riskof trauma to surrounding tissues.

Laparoscopy involves the placement of trocar ports according toanatomical landmarks. The number of ports usually varies with theintended procedure and number of instruments required to obtainsatisfactory tissue mobilization and exposure of the operative field.Although there are many benefits of laparoscopic surgery, e.g., lesspostoperative pain, early mobilization, and decreased adhesionformation, it is often difficult to achieve optimal retraction of organsand maneuverability of conventional instruments through laparoscopicports. In some cases, these deficiencies may lead to increased operativetime or imprecise placement of components such as staples and sutures.

Steerable catheters are also well known for both diagnostic andtherapeutic applications. Similar to endoscopes, such catheters includetips that can be directed in generally limited ranges of motion tonavigate a patient's vasculature. There have been many attempts todesign endoscopes and catheters with improved steerability. For example,U.S. Pat. No. 3,557,780 to Sato; U.S. Pat. No. 5,271,381 to Ailinger etal.; U.S. Pat. No. 5,916,146 to Alotta et al.; U.S. Pat. No. 6,270,453to Sakai, and U.S. Pat. No. 7,147,650 to Lee describe endoscopicinstruments with one or more flexible portions that may be bent byactuation of a single set of wires. The wires are actuated from theproximal end of the instrument by rotating pinions (Sato), manipulatingknobs (Ailinger et al.), a steerable arm (Alotta et a/.), by a pulleymechanism (Sato), or by manipulation of complementary portions (Lee).U.S. Pat. No. 5,916,147 to Boury et al. discloses a steerable catheterhaving four wires that run within the catheter wall. Each wireterminates at a different part of the catheter. The proximal ends of thewires extend loosely from the catheter so that the physician may pullthem. The physician is able to shape and thereby steer the catheter byselectively placing the wires under tension.

Recently, surgical instruments, including minimally invasive surgicalinstruments, have been developed that are more ergonomic and which havea wider range of motion and more precise control of movement. Theseinstruments may include mechanisms that articulate using a series oflinks coupled with one or more sets of tension bearing members, such ascables. As with conventional instruments used in minimally invasivesurgery, rotation of the shaft and the end effector with respect to thehandle is an important feature of cable and link type instruments to aidwith dissecting, suturing, retracting, knot tying, etc. Ergonomic,flexible, and intuitive mechanisms that facilitate manual control andplacement of the end effectors of such instruments are also importantfactors as medical procedures become more advanced, and as surgeonsbecome more sophisticated in operating abilities. Further improvementsin the features and design of surgical instruments are desirable.

SUMMARY OF THE INVENTION

It may at times be desirable to maintain the orientation orconfiguration of the distal end of steerable or articulating instrumentsthat have use in medical fields or non-medical applications. Thisinvention provides methods and devices for locking or otherwisemaintaining the shape and orientation of steerable and articulatinginstruments.

Embodiments of the invention include a tool that includes a distalportion and a proximal portion, an articulation mechanism, and anarticulation lock. In some embodiments of the tool, the tool is formedical applications, such as is a surgical or diagnostic tool. Thearticulation mechanism manipulates the angular orientation orconfiguration of the distal portion; it includes a pair of links, eachpair including a proximal link and a distal link spaced apart from eachother. The mechanism is adapted such that movement of the proximal linkcauses corresponding relative movement of the distal link. The relativemovement of the distal link that corresponds to the proximal linkmovement may either mirror the movement of the proximal link or bereciprocal to it.

The articulation lock has an engaged state and a disengaged state,wherein in the engaged state the articulation lock impedes movement ofthe proximal link and corresponding relative movement of the distallink. In some embodiments the impeding of movement is a partial impedingof movement; in other embodiments the impeding is a substantial blockingor preventing of movement. In some embodiments impeding the movement ofthe proximal link causes the impeding of the corresponding relativemovement of the distal link.

In some embodiments the tool further includes an end effector disposedat the distal portion. In some embodiments the end effector includes asurgical or diagnostic mechanism. In some embodiments the tool includesan end effector actuator disposed at the proximal portion. In someembodiments the tool includes a handle at a proximal end of the tool,and the handle includes the end effector actuator.

Some embodiments have an articulation lock that includes a link frictionincreasing element, such that when the lock is engaged, increasedfriction impedes movement of the links. Increasing friction canpartially impede link movement such that the link movement is malleable.Increasing friction can also fully impede link movement such that linkmovement is substantially blocked or prevented. Thus at the baselinelevel of friction that manifests on the link surfaces, the links can beconsidered freely moveable. With increasing levels of friction, linkmovement is such that the articulation mechanism as a whole ismalleable, and with further increase in friction, the articulationmechanism seizes such that there is substantially no movement. With thearticulation mechanism in an articulated configuration, application offriction can prevent movement of links from that articulatedconfiguration.

Some embodiments of the articulation mechanism include tension loadbearing members connecting the links of link pairs; some of theseembodiments include an articulation lock that includes a tension memberadjusting mechanism to increase tension on the members. Some embodimentsof tension load bearing members include cables, and such members mayfrequently be referred to simply as cables. Increasing tension on thecables increases friction on link surfaces that impedes link movement.As summarized above, increasing friction with a cable tension adjustingmechanism can impede movement of links such that they can move malleablyor links may be substantially unable to move.

In some embodiments, the articulation lock includes a rigid element,which when the lock is engaged, is disposed such that it extends atleast from a point proximal to the proximal link to a point at leastdistal to the proximal link. In other embodiments, the articulation lockincludes a malleable element, which when the lock is engaged, isdisposed such that it extends at least from a point proximal to theproximal link to a point at least distal to the proximal link. Thearticulation lock embodiments that include a malleable locking elementare able lock the links in an articulated configuration.

In addition to an articulation mechanism and an articulation lock, someembodiments further include an end effector disposed at the distalportion; the end effector may comprise a surgical or diagnosticmechanism. The tool may further include a handle at the proximal end ofthe tool, and the handle may comprise an end effector actuator.

In embodiments of the tool, the relative movement of the distal linkthat corresponds to the movement of the proximal link in someembodiments may be reciprocal to the movement of the proximal link; inother embodiments the movement of the distal link may mirror themovement of the proximal link.

In some embodiments the articulation mechanism includes multiple pairsof corresponding links, a proximal link on the proximal portion of thetool and a distal link on the distal portion of the tool, such thatmovement of the proximal link causes corresponding relative movement ofthe distal link. Thus in typical embodiments, the proximal link of apair that is most proximal on a tool operably corresponds to the distallink that is most distal on the tool. Similarly, the most distalproximal link corresponds to the most proximal distal link. Accordingly,intermediate proximal links accordingly correspond to intermediatedistal links.

In addition to an articulation mechanism and an articulation lock, someembodiments further include an end effector disposed at the distalportion; an end effector actuator disposed at the proximal portion; ashaft disposed between the end effector and the end effector actuator;such that movement of the distal link causes angular movement of the endeffector with respect to the shaft. In some of these embodiments, thearticulation mechanism includes multiple pairs of links, each pairincluding a proximal link on the proximal portion of the tool and adistal link on the distal portion of the tool, such that movement of theproximal link causes corresponding relative movement of the distal linkand angular movement of the end effector with respect to the shaft.

In some of the tool embodiments with an end effector, an end effectoractuator, a shaft, and multiple pairs of links, the articulationmechanism includes tension load bearing members connecting the links andthe articulation lock includes a tension load bearing member tensionadjusting mechanism configured to increase tension on the members. Insome embodiments the tension load bearing members comprise cables,accordingly, such tension load bearing members may be referred to ascables; accordingly, the tension load bearing member adjusting mechanismmay be commonly referred to as a cable tension adjusting mechanism Insome embodiments, the cable tension adjusting mechanism is disposedbetween the proximal and the distal links; in other embodiments thecable tension adjusting mechanism is disposed proximal to the mostproximal link. In some of these embodiments, the cable tension adjustingmechanism includes a threaded member; in other embodiments, the cabletension adjusting mechanism includes a cam locking lever configured toincrease the length of the shaft, thereby increasing tension on thecables. The cable tension adjusting mechanism, whether tensioned by athreaded member or a cam lever or any other mechanism, acts to vary thedistance between the proximal and distal links. By such varying ofdistance, friction that resists movement between links can vary. Thesejust-summarized embodiments of an articulation lock can lock links in anarticulated configuration as well as in an unarticulated configuration.

In some of the tool embodiments with an end effector, an end effectoractuator, a shaft, and multiple pairs of links, the articulation lockincludes a locking rod disposed in a channel formed in one or morelinks. In some embodiments, the locking rod is rigid; in some it ismalleable. When the locking rod is malleable, the articulation lock canlock links in an articulated configuration.

In some of these embodiments with an end effector, an end effectoractuator, a shaft, and multiple pairs of links, the articulation lockincludes a locking sleeve fitted over the multiple proximal links. Insome embodiments, the locking sleeve is rigid; in some it is malleable.When the locking sleeve is malleable, the articulation lock can locklinks in an articulated configuration.

In some of these just summarized tool embodiments with an end effector,an end effector actuator, a shaft, and multiple pairs of links, thearticulation lock includes a rigid element which, when engaged, isdisposed at least from a point proximal to the most proximal link to atleast to a point distal to the most distal proximal link. In some ofthese embodiments, the rigid element is disposed adjacent to theproximal links when in the engaged state. In some of these embodiments,the rigid element includes a sleeve that at least partially surroundsthe proximal links when in the engaged state. In some of theseembodiments, the sleeve is slidably mounted on the tool. In some ofthese embodiments with a slidable sleeve, the sleeve is disposed distalto the proximal links when in the disengaged state.

Embodiments of the invention include methods for using a tool, the toolcomprising a distal portion and a proximal portion, an articulationmechanism and an articulation lock, the method including changing theposition of the lock. In some embodiments, the tool is a medical toolconfigured for surgical or diagnostic methods. The articulationmechanism is for manipulating angular orientation of the distal portion,the articulation mechanism comprising at least one pair of links, thepair comprising a proximal link on the proximal portion and a distallink on the distal portion, the mechanism adapted such that movement ofthe proximal link causes corresponding relative movement of the distallink and the distal portion of the tool. The articulation lock has adisengaged state wherein the links move freely, and an engaged statewherein the lock impedes movement of the proximal link and correspondingrelative movement of the distal link.

The tool may further include an end effector disposed at the distalportion of the tool, such that movement of the distal portion of thetool moves the end effector. The tool may further include an endeffector actuator disposed at the proximal portion of the tool, suchthat moving the end effector actuator causes moving of the proximallink. In some embodiments, the tool may include a handle at the proximalend of the tool, and the handle may comprise the end effector actuator.In addition to an end effector disposed at the distal portion and an endeffector actuator disposed at the proximal portion, the tool may furtherinclude a shaft disposed between the end effector and the end effectoractuator; wherein movement of the distal link causes angular movement ofthe end effector with respect to the shaft.

The method of changing the position of the lock may be applied to a lockin a disengaged state, and wherein the changing the position comprisesengaging the lock. Engaging the lock may be applied to a tool whereinthe articulation mechanism comprises tension load bearing members(cables for example), connecting the links and the articulation lockcomprises a tension load bearing member (cable) tension adjustingmechanism configured to increase cable tension when engaging the lock.Engaging a lock with a cable tension adjusting mechanism may be appliedto an articulation mechanism when it is in either an unarticulatedconfiguration (which can be understood as a neutral or straightconfiguration), or it can be applied to an articulation mechanism whenit is in an articulated configuration, in which case the articulatedconfiguration is maintained as the mechanism is locked. Engaging a lockwith a cable tension adjusting mechanism may include increasing tensionon cables such that movement of the articulation mechanism is partiallyimpeded; and by having its movement partially impeded, the articulationmechanism becomes malleable. Engaging a lock with a cable tensionadjusting mechanism may also include increasing tension on the cablessuch that movement of the articulation mechanism is substantiallyblocked. Exemplary embodiments of a lock including a cable tensionadjusting mechanism include a threaded element for increasing tension onthe cables, and a cam lever mechanism for adjusting the length of theshaft, lengthening the shaft having the effect of increasing tension onthe cables.

The changing of position such that the lock becomes engaged may beapplied to a tool with a lock that includes a rigid element, and whereinengaging the lock comprises placing the rigid element where it extendsfrom a point proximal to the proximal link to a point distal to theproximal link, and wherein engaging the lock substantially blocksmovement of the distal portion. In some embodiments, the rigid elementis a rod, in some embodiments the rigid element is a sleeve.

Engaging the lock may be applied to a tool with a lock that includes amalleable element, and wherein engaging the lock comprises placing thelock in a position where it extends from a point proximal to theproximal link to a point distal to the proximal link. Engaging a lockwith a malleable element may be applied to an articulation mechanismwhen it is in either a neutral or unarticulated configuration, or it canbe applied to an articulation mechanism when it is in an articulatedconfiguration, in which case the articulated configuration ismaintained. Exemplary embodiments of a malleable element include a rodand a sleeve.

The method of changing the position of the lock may be applied to a lockin an engaged state, and wherein the changing the position comprisesdisengaging the lock. Disengaging the lock may be applied to a toolwherein the lock comprises a cable tension adjusting mechanismconfigured to decrease cable tension when disengaging the lock. Thecable tension adjusting mechanism may include a threaded member fordecreasing tension in the cables. The cable tension adjusting mechanismmay include a cam lever for adjusting the length of the shaft.

Disengaging the lock may be applied to a tool wherein the lock comprisesa rigid element, and wherein the rigid element is removed from aposition where it extends from a point proximal to the proximal link toa point distal to the proximal link.

Disengaging the lock may be applied to a tool wherein the lock comprisesa malleable element, and wherein the malleable element is removed from aposition where it extends from a point proximal to the proximal link toa point distal to the proximal link.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity inthe claims that follow. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawings which are briefly described below.

FIG. 1 is a front perspective view of an articulatable surgical tool.

FIG. 2 is perspective view of a surgical tool in an articulatedposition.

FIG. 3 is an exposed side view of a surgical tool with an end effectoractuator and an end effector both in an open position.

FIG. 4 is an exposed side view of a surgical tool with an end effectoractuator and an end effector both in a closed position.

FIG. 5 is a side view of the proximal portion of a tool, showing thehandle and proximal end of the shaft, with an articulation lockingsleeve in a distal and unlocked position.

FIG. 6 is a side view of the proximal portion of a tool, showing thehandle and proximal end of the shaft, with an articulation lockingsleeve in a proximal and locked position.

FIG. 7 is a side view of another embodiment of surgical tool, with adifferent embodiment of an articulation locking sleeve in distal andunlocked position, and with an end effector actuator and an end effectorboth in a closed position.

FIG. 8 is a side view of the embodiment shown in FIG. 7, but with thearticulation locking sleeve in a proximal and locked position.

FIG. 9 is a member of a series that extends through FIG. 24, showingdetails of a locking sleeve support mechanism, over which the sleeveslides. FIGS. 9-13 show the sleeve support mechanism in the unlockedposition. FIG. 9 is a cross-sectional focus on details of a pair ofshoulders formed in the sleeve, a corresponding pair of shoulder stops,a pair of detents on the sleeve that correspond to a pair of detents onthe sleeve support.

FIG. 10 is a full cross sectional side view of the sleeve and sleevesupport mechanism, with a circled portion representing the location ofdetail shown in FIG. 9.

FIG. 11 is a surface side view of the sleeve and sleeve supportmechanism corresponding to the cross-sectional view of FIG. 10.

FIG. 12 is a proximal-looking perspective view of the sleeve encircledaround the sleeve support, the sleeve in an unlocked position.

FIG. 13 is a distal-looking perspective view of the sleeve encircledaround the sleeve support, the sleeve in an unlocked position.

FIG. 14 is a member of a series that extends through FIG. 19 showing thesleeve and sleeve support mechanism in the locked position. FIG. 14 is aproximal-looking perspective view of sleeve encircled around the sleevesupport, the sleeve in a locked position.

FIG. 15 is a distal-looking perspective view of sleeve encircled aroundthe sleeve support, the sleeve in a locked position.

FIG. 16 is a cross-sectional side view of the sleeve and sleeve support,analogous to the view of FIG. 10, but with the sleeve in a lockedposition. The encircled area indicates the location of detail shown inFIG. 17.

FIG. 17 is a cross-sectional focus on details of a pair of shouldersformed in the sleeve, a corresponding pair of shoulder stops, a pair ofdetents on the sleeve that correspond to a pair of detents on the sleevesupport, the detail analogous to the view shown in FIG. 9, except thatthe sleeve is in a locked position.

FIG. 18 is a surface side view of the sleeve and sleeve supportcorresponding to the cross-sectional view of FIG. 16, the sleeve in alocked position.

FIG. 19 is a proximal-looking front end view of the sleeve and sleevesupport showing push tabs and pull tabs on the sleeve, and anti-rotationribs on the sleeve support.

FIG. 20 is a distal-looking perspective view of the sleeve without thesleeve support.

FIG. 21 is a proximal-looking perspective view of the sleeve without thesleeve support.

FIG. 22 is a side view of the sleeve without the support mechanism,proximal end up.

FIG. 23 is a perspective view of the isolated sleeve support mechanism.

FIG. 24 is a side view of the isolated sleeve support mechanism.

FIG. 25 provides two views of an articulation lock comprising a rod: Ashows a rod, which as depicted could either be a rigid rod or amalleable rod, oriented for insertion into the proximal portion of amulti-link articulating mechanism. B shows a malleable rod in placewithin the mechanism, holding the mechanism in an articulatedconfiguration.

FIG. 26 provides detail views of the links depicted in FIG. 25; Aproximal-looking perspective view; B is a distal looking perspectiveview.

FIG. 27 is a member of a series extending through FIG. 34 showinganother embodiment of the tool. FIG. 27 is a perspective view showing anembodiment that is configured with a cylindrical sleeve comprising aninternal threaded portion (not shown in this surface view), and withball and socket type links. This articulation lock embodiment is of atype that adjusts the tension bearing members that connect articulatinglinks, thereby increasing friction between links Encircled section ofFIG. 27 is shown in greater detail in FIG. 28.

FIG. 28 is an enlarged detail of FIG. 27, focusing on the cylindricalsleeve, and showing proximal links and a shaft extension portion.

FIG. 29 is a perspective view of the tool shown in FIG. 27, the tool inan articulated position.

FIG. 30 is a cross sectional view of the cylindrical articulation lockdepicted in FIGS. 27-34 showing the detail of the internal threadedportion with right hand and left hand threads that vary the tension oncables threaded through the links.

FIG. 31 is a member of a series extending through FIG. 34 showingdetails of components of the articulation lock. FIG. 31 shows the shaftextension portion, on the proximal portion of the shaft, from aproximal-looking perspective, with threads on the proximal portion.

FIG. 32 shows the shaft extension portion, on the proximal portion ofthe shaft, from a distal-looking perspective, with threads on theproximal portion, and showing holes and lumens for cables to passthrough.

FIG. 33 shows the threaded plug portion of the articulation lock,configured within the proximal portion of the articulation lock, from adistal-looking perspective, showing left hand threads, and proximalfacing concave bearing surface.

FIG. 34 shows the threaded plug portion of the articulation lock from aproximal-looking perspective, showing the lumens to permit cable sets topass through.

FIG. 35 is a side exposed view of the proximal portion of a tool with anarticulation lock comprising a locking lever and wedge that is locatedproximal to the most proximal links. This articulation lock embodimentis of a type that adjusts tension on the tension bearing members thatconnect articulating links, thereby increasing friction between links.The lever shown in an unlocked position.

FIG. 36 shows the articulation lock mechanism depicted in FIG. 35, butin a locked position, to prevent articulation.

FIG. 37 is a side exposed view of the proximal portion of a tool with anarticulation lock mechanism comprising a cylindrical locking sleeve witha translating locking disc connected to tension bearing members. Themechanism is located proximal to the most proximal links. Thisarticulation lock embodiment is of a type that adjusts tension ontension bearing members that connect articulating links, therebyincreasing friction between links. The mechanism is shown in an unlockedposition.

FIG. 38 shows the articulation lock mechanism depicted in FIG. 37, butin a locked position, to prevent articulation.

FIG. 39 is a side exposed view of the proximal portion of a tool with anarticulation lock comprising a locking mechanism comprising a disc witha lever, the mechanism located proximal to the proximal link. Thisparticular embodiment has only one pair of links and one set of tensionbearing members. This articulation lock embodiment is of a type thatadjusts tension on tension bearing members that connect articulatinglinks, thereby increasing friction between links. The mechanism is shownin an unlocked position.

FIG. 40 shows the articulation lock mechanism depicted in FIG. 39, butin a locked position, to prevent articulation.

FIG. 41 is a side view of an instrument with cam-based articulationlocking mechanism that is located between proximal and distal links. Thecam mechanism effectively increases the length of the shaft. Thisarticulation lock embodiment is of a type that adjusts tension on thetension bearing members that connect articulating links, therebyincreasing friction between links. The lever shown in an unlockedposition, thereby allowing articulation.

FIG. 42 is a detail view of the cam lock of FIG. 41. (A) a lockedposition, and (B) an unlocked position. The detail view emphasizes thedifference in relative location of the telescoping shaft components inthe two positions.

FIG. 43 is a perspective view of an articulating mechanism configured asa liver retractor, with a cam-based articulation locking mechanism thatis located between proximal and distal links. A shows the lock in theunlocked position; B shows the lock in the locked position. Thisembodiment has no dedicated end effector; the mechanism itself serves asthe engaging portion of the tool.

FIG. 44 is a perspective view of an articulating sheath device with anarticulation lock in the form of a cylindrical sleeve comprising aninternal threaded portion (not shown in this surface view) locatedbetween proximal and distal links. This articulation lock embodiment isof a type that adjusts tension on the tension bearing members thatconnect articulating links, thereby increasing friction between links.

FIG. 45 shows a set of pivoting links that have a single degree offreedom in (A) an articulated configuration and (B) in a straight,unarticulated position.

DETAILED DESCRIPTION OF THE INVENTION

Articulating Instruments

Steerable articulating instruments are described in U.S. Pat. No.7,090,637; US 2005/0107667; US 2005/0273084; US 2005/0273085; US2006/0111209, and US 2006/0111210. The articulating mechanisms of thetools described in those publications use multiple pairs of segments orlinks controlled, e.g., by multiple sets of cables, as well as toolsthat have a single pair of links, connected by a single set of cables,such as those described in U.S. Pat. No. 5,916,146. Depending upon thespecific design of the device, the links can be discrete segments (asdescribed, e.g., in U.S. Pat. No. 7,090,637) or discrete portions of aflexible segment (as described, e.g., in US 2005/0173085). Theinstrument may also include steerable or controllable links, e.g., asdescribed in US 2005/0273084, US 2006/0111209, and US 2006/0111210.Embodiments of the invention are not specific to any particular type oflink, and may include any type of link known in the art.

When using such articulating instruments, a user may manipulate theproximal end of the instrument, thereby moving one or more proximallinks of the articulation mechanism. This movement results in relativemovement of the distal link(s) corresponding to the proximal link(s). Itmay at times be desirable to lock or otherwise maintain the straight orbent shape of the instrument. In certain embodiments of this invention,the shape of the instrument is maintained by preventing movement of atleast one of the proximal links with respect to the rest of theinstrument.

FIGS. 1-6 show an articulatable tool 100 with an end effector 102 at itsdistal end and an end effector actuator 104 within a handle 106 at itsproximal end. Instrument 100 may be used, e.g., in a laparoscopicprocedure requiring grasping or cutting within a patient. Exemplaryembodiments of the tool 100 may also may useful in endoscopicprocedures, particularly when, as in some embodiments, the tool has aflexible shaft. Still other embodiments may be used for percutaneousprocedures, such as a catheter. Still other embodiments include devicesthat are directed toward natural orifice transluminal endoscopic surgery(“NOTES”). Embodiments of the invention may include a wide variety oftools, some with medical or diagnostic purposes, and others that areapplied to other types of tasks where the articulational capabilities ofthe tool provide benefit. Proximal articulation links 108 and 110 extenddistally from handle 106, and distal articulation links 112 and 114extend proximally from end effector 102. Proximal link 108 is connectedto and moves with handle 106. Likewise, distal link 112 is connected toand moves with end effector 102. An elongated shaft 116 is disposedbetween the proximal links and the distal links.

Proximal and distal links of paired links are operably connected bytension bearing members, such as cables. Embodiments may include tensionbearing members other than cables, but for simplicity and because cablesare a typical embodiment, tension bearing members may be commonlyreferred to as cables. A set of control cables 118 is attached toproximal link 108, extends through proximal link 110, shaft 116 anddistal link 114 and is attached to distal link 112. A second set ofcontrol cables 120 is attached to proximal link 110, extends throughshaft 116 and is attached to distal link 114. In this embodiment, thereare three control cables 118 in the first set and three control cables120 in the second set. It should be appreciated, however, that othernumbers of control cables may be used to connect corresponding proximaland distal links. In addition, mechanisms other than cables may be usedto connect corresponding links

As shown in FIG. 2, movement of handle 106 and proximal link 108 withrespect to proximal link 110 moves end effector 102 and distal link 112in a relative and corresponding manner. Likewise, movement of proximallink 110 with respect to shaft 116 moves distal link 114 with respect toshaft 116 in a relative and corresponding manner, also as shown in FIG.2. This relative articulation movement provides a way for a user toremotely manipulate the end effector through movement of the handle.

In the embodiment illustrated in FIGS. 1-4, the end effector 102 is apair of jaws. Actuation force is transmitted from end effector actuator104 through a transmission that includes a linearly movable compressionbearing member or rod 125 and a rotatable rod actuator 122, as shown inFIGS. 3 and 4. In some embodiments, the tension bearing member or rod isalso capable of bearing a compressive load, such that an end effectorcan be pushed by a force transmitted by the end effector actuator.

Other end effectors (surgical, diagnostic, etc.) and end effectoractuators may be used with the articulating tool of this invention. Insome embodiments, the distal links, themselves, can comprise an endeffector, such as, for example, a retractor. In some embodiments, themovable tension bearing member or rod may comprise any flexible tensionbearing material; in some embodiments Nitinol offers particularadvantages as it is sufficiently flexible to accommodate articulation,and yet resilient enough to carry a compressive load that allows the rodto open an end effector, such as a set of jaws.

Locking Articulation by Locking Proximal Links

In order to maintain a particular position of the end effector withrespect to the shaft, the articulating tool of this invention has anarticulation lock. In the embodiment shown in FIGS. 1-6, thearticulation lock includes a movable sleeve 130. In some embodiments thesleeve is rigid, as is the depicted example, but in other embodimentsthe sleeve may be malleable. Malleability may be imparted by variationsin design, such as with folds in the sleeve, or by increasing ofdimensions, or by use of malleable materials, or by use of combinationsof materials that individually contribute flexibility or stiffness, orby any combination of these approaches. In the unlocked position shownin FIGS. 1-5, sleeve 130 is distal to proximal links 108 and 110. In thelocked position shown in FIG. 6, however, sleeve 130 has been movedproximally to a position adjacent to and covering links 108 and 110 aswell as the proximal end of shaft 116, thereby blocking relativemovement between links 108 and 110 and between link 110 and shaft 116.In this locked position, relative movement between distal links 112 and114 and between link 114 and shaft 116 is prevented as well.

As shown in FIG. 6, a sleeve support mechanism 132 extends proximallyfrom shaft 116 to provide sliding support for sleeve 130. A distal stop134 provides a limit of distal movement of sleeve 130; a similar stop(not shown) is provided on or within handle 106 to limit proximalmovement of sleeve 130. Detents, ridges or other mechanisms may beprovided to maintain the sleeve in its proximal or distal positions andto provide tactile feedback to the user regarding the position of thesleeve.

FIGS. 7-24 show another embodiment of the invention. Articulatable tool700 has an end effector 702 at its distal end and an end effectoractuator 704 within a handle 706 at its proximal end. Tool 700 may beused, e.g., in a laparoscopic procedure requiring grasping or cuttingwithin a patient. Proximal articulation links 708 and 710 extenddistally from handle 706, and distal articulation links 712 and 714extend proximally from end effector 702. Proximal link 708 is connectedto and moves with handle 706. Likewise, distal link 712 is connected toand moves with end effector 702. An elongated shaft 716 is disposedbetween the proximal links and the distal links. The linkage betweenpairs of proximal and distal links may be with cables as in theembodiment of FIG. 1 or by any other suitable tension bearing members.Likewise, operation of end effector 702 may be as in the FIG. 1embodiment. Alternative embodiments of the tool could have as few as asingle pair of links, and a single cable set, or multiple pairs oflinks, and multiple cable sets. In any combination, the articulationlock now described would be appropriate and applicable

As in the embodiment of FIGS. 1-6, movement of handle 706 and proximallink 708 with respect to proximal link 710 moves end effector 702 anddistal link 712 in a relative and corresponding manner. Likewise,movement of proximal link 710 with respect to shaft 716 moves distallink 714 with respect to shaft link 716 in a relative and correspondingmanner. Such movements of the distal link, in alternative embodiments,can either reciprocate or mirror the movement of the proximal link,depending on whether the cables are strung directly (for reciprocalmovement), or whether they are rotated 180° (for mirrored movement).This relative articulation movement provides a way for a user toremotely manipulate the end effector through movement of the handle.

In order to maintain a particular position of the end effector withrespect to the shaft, the articulating tool of this embodiment has anarticulation lock. In some embodiments of the inventive lockingmechanism, as described further below in the “friction lockingembodiments” section, the locking mechanism provides a state that liesbetween free articulation and substantially blocked articulation suchthat movement can be characterized as being “impeded”. Embodiments ofmechanisms or methods described herein thus may also be characterized asmechanisms or methods that relate to permissibility of articulation suchthat articulation may occur freely, may occur not at all, or may occurin an impeded condition.

In the embodiment shown in FIGS. 7-24, the articulation lock includes amovable rigid sleeve 730. In the unlocked position shown in FIG. 7,sleeve 730 is distal to proximal links 708 and 710. In the lockedposition shown in FIG. 8, however, sleeve 730 has been moved proximallyto a position adjacent to and covering links 708 and 710 as well as theproximal end of shaft 716, thereby blocking relative movement betweenlinks 708 and 710 and between link 710 and shaft 716. In this lockedposition, relative movement between distal links 712 and 714 and betweenlink 714 and shaft 716, and relative movement of the end effector, areall prevented as well.

FIGS. 9-24 show details of a sleeve support mechanism 732 attached toand extending proximally from shaft 716 and its interaction with sleeve730. In FIGS. 9-13, sleeve 730 is in the unlocked position. In thisposition, a pair of shoulders 734 that are formed in sleeve 730 abut acorresponding pair of shoulder stops 736 formed on support mechanism732. In addition, a pair of detents 738 formed on sleeve 730 is justdistal to a corresponding pair of detents 740 formed on sleeve supportmechanism 732, as shown best in the detail view of FIG. 9. A centralbore 742 provides space for the cables and the rod 125, as seen forexample in FIG. 4. The links are proximal to the sleeve supportmechanism. The proximal face of the sleeve support part really has balland socket features in it (not shown). Caroming surfaces 735 on shoulderstops 736 and circumferential space 737 are provided for tool assemblypurposes. As sleeve 730 is drawn proximally over sleeve supportmechanism 732 during assembly, engagement of a proximal sleeve surfacewith caroming surfaces 735 to push shoulder stops radially inward intospace 737 to permit sleeve 730 to be drawn over the support mechanism.

Sleeve has pull tabs 744 to provide a grip for a user to move the sleeveproximally. Push tabs 746 provide a similar function for moving thesleeve distally. In the locked position shown in FIG. 7, pull tabs 744nest with grooves 745 formed in a rotation knob 747 that may, in someembodiments, be used to rotate end effector 702 with respect to handle706 and to lock the rotational position of the end effector. Furtherdetails of such a rotation knob and lock may be found in concurrentlyfiled US patent application “Tool rotation lock” of Hinman and Danitz,This nesting feature is optional with respect to the articulation lockof this invention.

When pulled proximally, clearance channels 748 on the inner surface ofsleeve 730 permit the sleeve to slide proximally with respect to detents740. In addition, anti-rotation channels 750 in sleeve 730 cooperatewith anti-rotation ribs 752 in support mechanism 732 to prevent sleeve730 from rotating as it moves proximally and distally.

FIGS. 14-19 show details of the sleeve and sleeve support mechanism ofthis embodiment in the locked position. As sleeve 730 is drawnproximally to provide the articulation lock, a pair of tabs 754 onsleeve 730 pass through recesses 756 in support mechanism 732 to engagestop shoulders 758. In addition, as tabs 754 draw toward shoulders 758,detents 738 on sleeve 730 pass over detents 762 on support mechanism 732to hold sleeve 730 in the locked position and to provide further tactilefeedback about the state of the articulation lock. FIGS. 20-22 showfurther views of sleeve 730, and FIGS. 23-24 show further views ofsleeve support mechanism 732.

Typically, rigid elements lock an articulation mechanism in a singleconfiguration, generally “straight”. Some embodiments of rigid elementsmay not be “straight” however; as some embodiments may assume a bent orcurved configuration that is desirable for a particular application.Thus, as useful as it may be for many applications, rigid elementlocking, in contrast to malleable locking, is a locking that istypically limited to a single locked configuration. Malleable lockingmechanisms, in contrast, provide an ability that rigid elementsgenerally lack, which is to lock an articulating mechanism in any of thevarious articulated configurations that the mechanism can assume.

As will be described further below, other features come witharticulating mechanisms that have a locking mechanism based on frictionlocking, in contrast to the rigid or malleable element locking. Thisfriction-based type of locking allows various locked states that includea substantially blocked movement (like that of rigid element lockembodiments), as well as a partially-impeded movement (similar but notidentical to that of malleable element lock embodiments). The motionimpedance provided by the friction lock is adjustable or tunable indegree in accordance with the degree to which tension in the mechanismis adjusted. The friction lock embodiments and features are describedfurther in a section below.

FIGS. 25 and 26 show a locking rod embodiment of an articulation lock.FIG. 25A shows a simple rod 201 aligned to be inserted into anarticulating tool 200 with a set 202 of multiple links (15, in thiscase). Only the proximal portion of the tool is seen, it has no proximalhandle, but has a shaft 205. FIG. 25A could represent either a rigid rodor a malleable rod, depending on the nature of the material from whichthe rod is fabricated. FIG. 25B shows the rod as a malleable rod 201,after insertion into tool 200, and after the articulating mechanism hasbeen manipulated so as to articulate it. In the present state, themechanism is locked. FIG. 25B also provides a perspective view of theproximal face of the most proximal link 210, where it can be seen thatthe rod has entered and occupies a channel 215 in the link, such channelbeing continuous throughout the links in the mechanism. FIGS. 26A and26B show such a link, from a distal-looking and proximal-lookingperspective, respectively. The rod channel 215 is in the form of an opengroove; in other embodiments, the channel could be circumferentiallyclosed.

It can be seen that the locking rod, whether rigid or malleable,operates by being disposed proximal to each proximal link whose movementit blocks to a point distal to each blocked proximal link. Inasmuch asthe illustrated tool embodiment 200 includes 15 links, the rod isdisposed proximal to the most proximal link, and extends to a pointdistal to the distal-most proximal locked link. In some embodiments, aproximal subset of the proximal links may be locked by a rod, leavingthe more distal of the proximal links unlocked. The rod does not extendinto the distal region of the articulating mechanism; it exerts itslocking force only by way of locking the proximal links. The proximallinks that are locked by a rod transfer the blockage of their movementto the distal links by way of the tension bearing members connectingthem.

Friction Locking Embodiments: Locking by Adjusting Tension of TensionBearing Members

Articulation lock embodiments in this section are generally of a typethat involves locking movement between articulating links with friction.Links, as described above, typically occur in proximal-distal pairs thatare operably connected to each other by a set of tension bearingmembers, such as cables. The cables are configured in such a way thatmovement of the proximal link transfers to the corresponding orcomplementary distal link of the pair by way of the cables or othertension bearing members. Some embodiments of articulating mechanism towhich friction-based locking may be applied include ball and socketlinks, but other types of links, such as single-degree-of-freedompivoting links, are also included as embodiments (FIGS. 45 and 46).

Friction-based locking mechanisms described herein include a mechanismthat adjusts the tension of the tension bearing members. Tension can beincreased either by decreasing the length of cables connecting the linkswhile the distance between links remains unchanged, or by increasing thelength of the distance between links, while not changing the length ofthe connecting cables. Each approach is exemplified by embodimentsbelow.

In a neutral or unlocked position, the tension of cables is at abaseline level according to specifications appropriate for the mechanismand its application. With increasing tension, as applied by a tensionadjusting mechanism, pressure between the links increases, whichincreases friction between the links, and the friction impedes movementacross the interface between the links. Thus, by such lockingmechanisms, an articulating mechanism can move from (1) an unlockedstate, where links are freely movable, or movable at some baseline levelof freedom, to a state (2) where movement between links is partiallyimpeded and wherein the articulation mechanism as a whole is malleable,to a state (3) where movement between links is substantially blocked,and the articulation mechanism as a whole is “seized”.

The friction locking mechanisms have other features that distinguishthem from rigid- or malleable-element-based mechanisms described above.One feature characteristic of friction locking, per describedembodiments, involves a locking process that occurs with substantialuniformity throughout the proximal-to-distal length of the lockedportion of the articulating mechanism. (This locking process as a wholediffers from the rigid or malleable element-based approaches where thedirect locking action of the mechanism occurs in the one or moreproximal links, and wherein the tension bearing members transfer thatlocked state to the distal links, causing them to lock in this secondarymanner.) The locked portion of an articulating mechanism need notinclude the entire length. An inner portion of the length (i.e., a setof link pairs including the more distal of the proximal links and themore proximal of the distal links) may be locked, leaving the outerportion of the length (i.e., a set of link pairs including the moreproximal of the proximal links and the more distal of the distal links)free to articulate. For example (referring to FIG. 4) tension could beincreased in cable set 120 (which connects links 110 and 114) whileleaving cable set 118 (which connects links 108 and 112) withoutadditional tension beyond baseline. In this case, links 110 and 114 arelocked, while 108 and 112 are free to articulate.

FIGS. 27-34 show an embodiment of this invention that utilizes afriction-based locking mechanism. As in the above-described embodiments,articulatable tool 800 has an end effector 802 at its distal end and anend effector actuator 804 within a handle 806 at its proximal end. Tool800 may be used in any of a variety of types of procedures, includingfor example, laparoscopic procedures that require grasping, cutting, orsealing within a patient; it could further be used percutaneously as acatheter, and in an embodiment that includes a flexible shaft, it couldbe used in endoscopic procedures.

Tool 800 has ball and socket links consisting of proximal active links808 and 810 separated by a bushing 809. Proximal link 808 is connectedto and moves with handle 806. A second proximal bushing 811 is disposedbetween link 810 and an articulation lock (described in more detailbelow) on the proximal end of the shaft 816. The bushings have convexsurfaces interacting with corresponding concave surfaces on the links808 and 810 and on the proximal end of the articulation lock. Likewise,distal active links 812 and 814 are separated by a bushing 813, and asecond distal bushing 815 is disposed between the distal end of shaft816 and active link 814. Distal link 812 is connected to and moves withend effector 802. Like their counterparts, spacer links 813 and 815 haveconvex surface on their ends which interact with corresponding concavesurfaces on active links 812 and 814 and on the distal end of shaft 816.Sets of articulation cables 818 and 820 extend between the proximal anddistal active links to control the articulation of the tool. Operationof end effector 802 may be as in the FIG. 1 embodiment, where movementof end effector actuator 804 moves rod 825 to open and close the endeffector jaws. Further details of the types links suitable for use withthis invention, such as ball and socket joints, and pivotingsingle-degree-of freedom joints, or any type of joint where frictionaffects the movement of links relative to each other, may be found in US2005/0273084 US 2006/0111209, and US 2006/0111210.

As in the other embodiments, movement of handle 806 and proximal link808 with respect to proximal link 810 moves end effector 802 and distallink 812 in a relative and corresponding manner. Likewise, movement ofproximal link 810 with respect to shaft 816 moves distal link 814 withrespect to shaft 816 in a relative and corresponding manner. Thisrelative articulation movement provides a way for a user to remotelymanipulate the end effector through movement of the handle, as shown inFIG. 29.

In order to maintain a particular position of the end effector withrespect to the shaft, the articulating tool of this embodiment has anarticulation lock. In this embodiment, the articulation lock is amechanism that elongates the tool's shaft 816 with respect to thearticulation cable sets, thereby applying tension to the ball and socketinterfaces of the links. This interface tension provides sufficientfriction to maintain the orientation of the links with respect to eachother, thereby locking the articulating tool and preventing furtherarticulation. It should be appreciated that the tool can be locked in astraight configuration (as shown in FIG. 27) or in a bent configuration(as shown in FIG. 29).

FIGS. 30-34 show details of the articulation lock of this embodiment.Right handed threads 832 are formed on the exterior of a shaft extension817 on the proximal end of shaft 816. Surrounding the proximal end ofshaft extension 817 is a cylindrical sleeve 830 having an internalthreaded portion 834 with right handed threads corresponding to threads832 on shaft extension 817. Also disposed within the bore of sleeve 830is a threaded plug 836 with left handed threads corresponding to asecond internal threaded portion 838 of sleeve 830 that also has lefthanded threads. The proximal end of plug 836 has a concave bearingsurface 840 that interacts with the convex bearing surface of bushing811.

In its unlocked position, the articulation lock of this embodiment isrotated clockwise to a position in which the cable sets 818 and 820 areslack enough to permit the active and spacer links to move with respectto each other. To lock or prevent articulation, sleeve 830 is rotatedcounterclockwise, thereby moving plug 836 and shaft extension 817 awayfrom each other. This elongation of the effective length of the toolapplies tension to the cables and forces the convex and concave bearingsurfaces of the bushings and links against each other. The frictioncaused by this tight engagement locks the tool in its articulatedposition.

Ball plunger 842 extends radially inward from sleeve 830 and acts as adetent by extending into a slot 84, a slot that the ball plunger hits atdifferent axial locations. The slot takes the place of a single hole forthe ball of the ball plunger to fall into. In this way, the ball plungerand a single slot can form multiple stop detents at each 360 degreerotation of the sleeve 830. Multiple ball plungers and slots can be usedto increase the resolution of the detents. Counter torque pins 846 aredisposed in corresponding holes in the plug and shaft extension,respectively. These pins keep the shaft extension 817 and the plug 836at the same angular orientation and allow the two components totranslate axially with respect to each other when the sleeve 830 isrotated. Further details of the articulation lock are shown in FIGS.31-34. FIG. 32 shows lumens 850 to permit cable sets 818 and 820 to passthrough the shaft extension. Hole 852 (FIG. 32) is the hole that countertorque pins 846 ride in (this hole and the one 180 degrees from it), andFIG. 34 shows lumens 848 to permit cable sets 818 and 820 to passthrough the plug 836 Holes 853 In (FIG. 34) accept the counter torquepins. Call it holes 848 (FIG. 33) are for articulation cables.

FIG. 35 is a side exposed view of the proximal portion of a tool 900with an articulation lock comprising a locking lever 905 and lockingwedge 910 fitted into a circular locking groove 920 with rampedsurfaces. The groove 920 is formed from the proximal face of proximallink 108 and the distal face of a locking disc 915. Cables of cable set118 go through oversize holes in link 108 and are anchored in lockingdisc 915. This articulation lock embodiment is of a type that adjuststension on the cables that connect articulating links, therebyincreasing friction between links. The lever 905 is shown in an unlockedposition. FIG. 36 shows the articulation lock mechanism depicted in FIG.35, but in a locked position, to prevent articulation.

Locking wedge 910 is narrow at its point of attachment to the lever 905,flaring outward from its base. Locking groove 920 is wide at its radialbase, and narrows as it progresses radially outward. The slopingproximal and distal walls of the groove may be considered ramps; theangles of the ramps complement the angles of the proximal- anddistal-facing surfaces of the wedge 910. Locking disc 915 encircles aproximally-projecting spindle portion 109 of link 108, and is slidableon that portion. Locking disc 915 is pulled or biased distally by thetension of cables 118, its distal movement is stopped by a shoulder 925on the proximal face of link 108. The effect of the action of thelocking lever is to pull the locking wedge 910 radially outward ofgroove 920; in so doing, the wedge 910 pushes the locking disc 915proximally. As the disc 915 is pushed proximally, it pulls on the cablesof cable set 118, thereby increasing their tension. By this action, thearticulation lock is locked. This locking action is variable, accordingto the degree to which the wedge is pulled out of its groove.

In FIGS. 35 and 36, the locking lever 905 is bent at the point ofpivotable connection 906. A slot 907 accommodates the linkage to thebase of locking wedge 910. The slot is sufficiently wide to accommodatemovement of wedge distally and proximally, as it moves according to therelative proximal-distal position of the wedge. The locking lever 905depicted here is a mere example of any number of mechanisms that couldcontrollably and reversibly move the wedge 910. The lever as depictedhas no tine to fix the locking lever in any position, but manymechanisms are known to fix the position of the lock. A ratchetmechanism, for example, could provide a variable level of lockingtension in the cables, such that the mechanism could be fixed in amalleable condition. In another variation, the angle of the lockingwedge 910 could be shallow enough such that the locking mechanism, whenlocked, stays in place due to friction between the locking wedge 910 andthe walls of the grove 920. In other words, the angle between the matingcomponents could be shallow enough that the tension in the cables couldnot back-drive the mechanism. In this case, the locking lever 905 wouldneed to be pushed upward to unlock the mechanism.

FIG. 37 is a side exposed view of the proximal portion of a tool 1000with an articulation lock mechanism comprising a cylindrical lockingsleeve 1030 with a translating locking disc 1015 connected to tensionbearing members. This articulation lock embodiment is of a type thatadjusts tension on tension bearing members that connect articulatinglinks, thereby increasing friction between links Locking sleeve 1030 isrotatable around proximal link 1108; the sleeve has an internal threadedportion which mates with external threads of locking disc 1015, movingthe disc proximally and distally depending on the direction the lockingsleeve is turned. Locking disc 1015 encircles a proximally-projectingspindle portion 1109 of link 108, and is slidable on that portion.Locking disc 10515 is pulled or biased distally by the tension of cables1036, its distal movement is stopped by a shoulder 1125 on the proximalface of link 1108. A slot 1032 in the sleeve mates with a flange 1034 inlink 1108 to prevent translating movement either proximally or distally,as the sleeve is rotated. As the proximal-distal position of the sleeveis thus fixed, rotational translation force is imparted to the lockingdisc 1015, which due to its connection to the cables 1036, therebyadjusts the tension on the cables. Counter torque pins (not shown)similar to counter torque pins 818 in FIG. 30 could be provided toprevent the locking disk 1015 from rotating when the locking sleeve 1030is rotated.

The mechanism is shown in an unlocked position in FIG. 37, and in lockedposition in FIG. 38, where the locking disc 1015 can be seen to havemoved to a more proximal position. By moving proximally with the cablesattached, the cables have thus accumulated a higher level of tension.

The particular embodiment shown in FIGS. 37 and 38 shows a set of threeproximal links and a single set of cables. This number of links andnumber of cable sets is only an example of combinations of links andcable sets to which friction based articulation locking mechanisms, perembodiments described herein may be applied. Articulation locks of alltypes described herein may be applied to embodiments without limitationto the number of links and without regard to the number of cable sets,connecting the links, nor to the number of cables in the sets. Further,articulation locks that are friction-based, can be applied to anyarticulating mechanism that makes use of links whereby an increase inthe tension of cables connecting the links causes an increase infriction as the surfaces of articulating links as they move relative toor across each other.

FIG. 39 is an exposed side view of the proximal portion of a tool 1100with an articulation lock comprising a locking mechanism comprising alocking disc 1115 and with a side-mounted locking lever 1105, themechanism located proximal to the proximal link This particularembodiment has only one pair of links and one set of tension bearingmembers. As with the previously described embodiment the cables 1103 ofthe cable set slip through proximal link 108 and terminate in thelocking disk 1115. Adjusting the relative proximal-distal position ofthe locking disc through the action of the lever 1105, thus adjuststension on the cables. A tine 1110 on the handle secures the lever inthe locked position (compare FIGS. 39 and 40). The tine 1110 is but oneof many mechanisms that could secure such a lever, other embodimentsinclude, for example, a rack of teeth such that the lever could be heldat various positions, thereby creating various levels of tension in thecables, and thereby, in a mid-position, fixing the articulationmechanism in a malleable state.

The mechanism of FIG. 39 is shown in an unlocked position. FIG. 40 showsthe articulation lock mechanism depicted in FIG. 39, but in a lockedposition, to prevent articulation. In terms of the nature of thisembodiment in general terms, this articulation lock embodiment is of atype that adjusts tension on tension bearing members that connectarticulating links, thereby adjusting the amount of friction betweenlinks. In some embodiments, a locking disc (like disc 115) can beintegrated into a link 110 (see FIGS. 1-4 for reference). In such aconfiguration inner links 110 and 114 can be locked, while outer links108 and 112 remain free to articulate.

FIG. 41 is a side view of a tool 1100 with cam-based articulationlocking mechanism that is located between proximal and distal links.This articulation lock embodiment is of a general type that adjuststension on the tension bearing members that connect articulating links,thereby increasing friction between links. In this embodiment, the linktension is adjusted by varying the effective length of the shaft, andmore specifically, shaft length is varied by a cam mechanism 1210. Thelever is shown in an unlocked position, thereby allowing articulation.

FIG. 42 is a detail view of the cam lock of FIG. 41. (42A) a lockedposition, and (42B) an unlocked position. The detailed views of FIG. 42emphasize the difference in relative location of the telescoping shaftcomponents in the two positions. FIG. 42 provides a detail of cammechanism 1210, which comprises three main components, a cam lever 1212,an inner shaft component 1214, and an outer telescoping shaft component1215. The cam lever 1212 comprises a cam surface 1213 that rotatesacross the surface of flange 1216, a portion of the inner telescopingshaft component 1214. As the cam lever 1212 moves from an unlockedposition to a locked position, the camming action forces the outertelescoping shaft component 1215 forward with respect to the inner shaftcomponent 1214, thereby lengthening the shaft. While the length of theshaft increases, the distance between the termination points of thecables in the links at the proximal and distal ends of the articulatingmechanism increases, thereby increasing tension on the cables. Asdescribed above, increased tension in the cables is distributed throughthe length of the cable, increasing the friction associated withmovement across the abutting surfaces of links on the proximal anddistal ends of the articulating mechanism. Such friction impedeslink-link movement to a degree that varies between converting freemovement to malleable movement, to a seizure that substantially preventsmovement.

FIG. 43 is a perspective view of tool 1300 with an articulatingmechanism configured as a liver retractor, with a cam-based articulationlocking mechanism 1310 that is located between proximal and distallinks: 43A shows the locking mechanism in the unlocked position; 43Bshows the locking mechanism in the locked position. The lockingmechanism and its operation are substantially the same as described inthe preceding embodiment. This embodiment has no other specific endeffector; the mechanism itself serves as the engaging portion of thetool. This embodiment provides an example of a tool wherein thearticulating mechanism itself, to which the inventive articulation lockis applied, is the functional portion of the tool, not a dedicated endeffector Embodiments of the articulation locks disclosed in this presentapplication may thus be appropriately fitted into devices such as theone shown in FIG. 43 as well as into many other similar devices such asthose disclosed in detail in U.S. Pat. No. 7,090,637 which is herebyincorporated by this reference.

FIG. 44 is a perspective view of an articulating sheath device 1400 withan articulation lock in the form of a cylindrical rotating sleevemechanism 1410 comprising an internal threaded portion (not shown inthis surface view) located between proximal and distal links. This typeof device can make use of any of the articulation lock embodimentsdescribed herein; the particular embodiment described herein is providedby way of example as to how such locks may be applied. This articulationlock embodiment is of a type that adjusts tension on the tension bearingmembers that connect articulating links, in this embodiment it increasestension by making the shaft 1412 longer, thereby increasing frictionbetween links. In the embodiment depicted, the shaft 1412 is rigid, butin other embodiments it may be flexible. The proximal portion of thedevice 1400 comprises a handle 1415, and emerging from the proximalportion of the handle is a set of proximal links 1420 that correspond toa distal set of articulating links 1421, emerging from the shaft 1412.The handle further comprises an entry port 1424 for a flexibleendoscopic tool or flexible endoscope 1425, which is shown in the figureadjacent to the entry port 1424 and also emerging from the distalportion of the articulating sheath. The articulating links 1420 and 1421are shown in greater detail in FIGS. 45 and 46, and described furtherbelow.

Embodiments of the inventive friction-based articulation locks describedherein may be applied to articulating mechanisms that utilize any typeof link that has a surface-to-surface relative motion with a neighboringlink. Ball and socket type links represent one example; other types oflinks appropriate for embodiments of the articulation lock mechanismdescribed herein include U.S. published patent applications.US2005/0273084, US2006/0111616, US2006/0111209, and US2006/0111210, allof which are hereby incorporated by this reference.

FIG. 45 shows a set of pivoting-hinge type links 1500. In (45A) the toptwo links are in pivoted in an articulated configuration, each onetipped at a hinge point where it has a single degree of freedom, and in(45B) all links are in a straight, unarticulated position. FIG. 45 showsa series of cable holes 1505 arrayed around the circumference of the rimof the link, and a large central bore 1510 The radial central bore canaccommodate other instruments, or components of an instrument thatcontrol an end effector, or for electrical wires, or for lasers or fiberoptical instruments. These pivoting-hinge type links are similar to theflex-hinge type of links described in U.S. patent application Ser. No.10/948,911, except for differences in specifics of the hinge (pivotingvs. flex). These pivoting hinge joints have one degree of freedom, andthereby differ from ball and socket joints, which have two degrees offreedom.

Important for the articulation locking is that each link is connected toits adjacent link by a connection whose movement can be impeded by anaxial load applied by increasing tension in the cables on which thelinks are strung. The impeding of movement can be either of a modesttype, in which the link movement becomes malleable, creating a mechanismas a whole that is malleable, or the movement can be substantiallyblocked or seized up when a sufficient axial load is applied. Whenmovement of links is substantially prevented, the mechanism as a wholebecomes locked in configuration, whether the mechanism is straight orarticulated.

While the inventive surgical instruments and devices have been describedin some detail by way of illustration, such illustration is for purposesof clarity of understanding only. It will be readily apparent to thoseof ordinary skill and in the art in light of the teachings herein thatcertain changes and modifications may be made thereto without departingfrom the spirit and scope of the appended claims. For example, while thearticulation mechanism and articulation lock embodiments described inhere have typically been in the context of tools with an articulatingmechanism comprising at least two links, the mechanisms may be used inan instrument comprising only a single link, a multiplicity of links,and with any number of cables or cable sets operably connecting thelinks. Further, the articulating mechanisms may be used in the absenceof many features commonly associated with some articulatableinstruments, such as handles, shafts, rotatability features, anddedicated end effectors. Finally, while the context of the invention isconsidered to be surgical or medical diagnostic procedures, thearticulation locking mechanisms or tool having such mechanisms may haveutility in other non-medical contexts as well.

What is claimed is:
 1. A method of using a tool, the tool comprising: adistal portion and a proximal portion, the distal portion including aplurality of distal links, each distal link being movable in multipledegrees of freedom about a link pivot disposed between adjacent distallinks, the proximal portion including a plurality of proximal links,each proximal link being movable in multiple degrees of freedom about alink pivot disposed between adjacent proximal links; an articulationmechanism for manipulating angular orientation of the distal portion,the articulation mechanism comprising multiple pairs of links, each paircomprising a proximal link on the proximal portion and a distal link onthe distal portion, the proximal link spaced apart from thecorresponding distal link along a longitudinal axis by a distance, andmultiple sets of tension load bearing members, each set connecting theproximal link and the corresponding distal link of one of the multiplepairs of links and terminating at the links of the pair, the mechanismadapted such that movement of the proximal link causes correspondingrelative movement of the distal link of the pair; and an articulationlock positioned between the distal portion and the proximal portion witheach set of tension load bearing members passing through thearticulation lock to connect the proximal link and corresponding distallink of one of the multiple pairs of links, the articulation lock havinga disengaged state wherein the links move freely, and an engaged statewherein the lock forces the adjacent distal links into frictionalengagement and forces the adjacent proximal links into frictionalengagement to impede movement of the proximal link and correspondingrelative movement of the distal link, the method comprising placing thearticulation lock in at least one of the disengaged state and theengaged state.
 2. The method of claim 1 wherein the tool is a medicaltool configured for surgical or diagnostic methods.
 3. The method ofclaim 1 wherein the tool further comprises an end effector disposed atthe distal portion of the tool, such that movement of the distal portionof the tool moves the end effector.
 4. The method of claim 1 wherein thetool further comprises a handle with an end effector actuator disposedat the proximal portion of the tool, such that moving the end effectoractuator causes movement of a proximal link of the plurality of proximallinks.
 5. The method of claim 1 wherein the tool further comprises anend effector disposed at the distal portion; an end effector actuatordisposed at the proximal portion; a shaft disposed between the endeffector and the end effector actuator; wherein movement of a distallink of the plurality of distal links causes angular movement of the endeffector with respect to the shaft.
 6. The method of claim 1 wherein thelock is in a disengaged state, and wherein the changing the position ofthe lock comprises engaging the lock.
 7. The method of claim 6 whereinthe articulation lock comprises a member tension adjusting mechanismconfigured to increase tension in the tension load bearing members toincrease friction between the links of the articulation mechanism whenengaging the lock.
 8. The method of claim 7 wherein the articulationlock in the engaged state is configured to maintain a firstconfiguration of the articulation mechanism, wherein the articulationmechanism was in the first configuration when the lock was engaged. 9.The method of claim 8 wherein the tension on the members is such thatmovement of links of the articulation mechanism is substantiallyblocked.
 10. The method of claim 7 further comprising placing thearticulation lock in a partially engaged state wherein the tension onthe members is such that movement between the links of the articulationmechanism is partially impeded and the articulation mechanism as a wholeis malleable.
 11. The method of claim 7 wherein the lock comprises athreaded element.
 12. The method of claim 7 wherein the lock comprises alever mechanism configured to adjust the length of the shaft.
 13. Themethod of claim 1 wherein placing the articulation lock in a disengagedstate comprises changing the position of the lock to reduce frictionbetween the links of the articulation mechanism.
 14. The method of claim13 wherein the articulation lock comprises a member tension adjustingmechanism configured to decrease tension on the tension load bearingmembers when placing the lock in the disengaged state.
 15. The method ofclaim 14 wherein the tension load bearing members comprise cables. 16.The method of claim 14 wherein the member tension adjusting mechanismcomprises a threaded member.
 17. The method of claim 1, wherein thearticulation lock positioned between the distal portion and the proximalportion comprises a member tension adjusting mechanism including aproximal component and a distal component, and wherein engaging the lockcomprises increasing the length of the tool by moving the proximalcomponent and the distal component away from each other.
 18. The methodof claim 17 wherein increasing the length of the shaft by moving theproximal component and the distal component away from each othercomprises increasing friction between the links of the articulationmechanism.